Seven newly recorded species of Achnanthidiaceae from Great Xing’an Mountains were reported in this paper. They are Rossithidium petersennii, Psammothidium acidoclinatum,Psammothidium grischunum,Psammothidium subatomoides, Psammothidium ventralis, Platessa conspicua,Platessa lutheri. Morphological features of these species were described in detail and the habitats of sampling sites were given. The Chinese description of the genus Rossithidium is provided.